The best flour for bread is that made from the spring wheat, grown in cooler climates, because it is richer in gluten than the winter wheat. The winter wheat flour is used more for cakes and pastries. Bread made with milk, is, of course, richer and more nutritious than that made with water, and bread made with potato water contains more starch; both of these retain their moisture longer than bread made without them. _Mold_, which sometimes forms on bread, is, like the yeast, a minute plant. It is floating about everywhere in the air, ready to settle down wherever it finds a suitable home. Moisture and heat favor its growth; hence bread should be thoroughly cooled before it is put into a jar or bread box. The bread box should be ventilated and kept in a cool place. _Rye bread_ contains a little more starch and less protein than wheat bread. It contains more water and holds its moisture longer. _Biscuits._ The objection to eating hot bread does not hold for baking powder or soda biscuits, if well cooked, because these cool more rapidly and they do not contain the yeast plant; hence, they do not ferment as does the bread. _Baking powder_ is made from bicarbonate of soda (baking soda) and cream of tartar. When these are brought in contact with moisture, carbon dioxid is liberated, and in the effort to escape it causes the dough to expand and become light. Breads made with pure baking powder are wholesome and, when light, are digestible. When made with cheap baking powder, however, in which alum or ammonia is employed, the stomach may be irritated by the chemical substances contained. The reason that the cook attempts to bake her biscuits, or anything made with baking powder, as quickly as possible after the baking powder comes in contact with the moisture, is that the dough may have the full effect of the expansion of the gas. If the room in which she mixes her dough is cool, or if her biscuit dough is left in a cool place, this is not important, as heat and moisture are both required for full combustion. Enough baking powder biscuit dough may be mixed at one time to provide biscuits every morning for a week, if buried in flour immediately after mixing so that it is kept cool and from the air. A portion may be cut off each morning and the remainder again buried in the flour. _Macaroni_ and _spaghetti_ are made from a special wheat flour known as Durum. They contain about seventy-seven per cent. of starch, little fat, and little protein. They may take the place of bread, rice, or potato at a meal. _Rice_ is a staple cereal in all tropical and temperate climates. It requires special machinery to remove the husk and the dark, outer skin of the kernel. The polished rice commonly used, is almost pure starch, and, like white flour, lacks the nutritive qualities contained in the husk or covering. It is seldom eaten within three months after harvesting and it is considered even better after two or three years. It requires thorough cooking.